Basic Guide to Pesticides: Their Characteristics and Hazards

The pesticide chemical in pure form (95-100% concentration) as it is manufactured by a chemical company prior to being formulated into wettable powders, dusts, emulsifiable concentrates, granules, etc.

A compound that causes excessive nerve transmission at (cholinergic) synapses by blocking ability of cholinesterase to break down acetylcholine into acetic acid and choline. Chemicals with this activity include poisons of the nerve gas type as well as pesticides of the organophosphate or carbamate class.

(auricular): A condition characterized by irregular convulsive movements of the aria of the heart, the number of impulses being great, and individual fibers acting independently
(ventricular): A condition characterized by fibrillary twitching of the ventricular muscle, with the impulses traversing the ventricles so rapidly that coordinated contractions cannot occur.

The Bt (Bacillus thuringiensis) bacteria produce a toxic protein lethal to caterpillars due to a unique condition in the caterpillar intestinal tract. The gene for the Bt protein has been transplanted into a corn plant producing transgenicBt corn. This is a patented life form.

A chemical class that includes insecticides. They may or may not act as anticholinesterases (or cholinesterase inhibitors). Includes the insecticides: methomyl, carbaryl, propoxur (which are cholinesterase inhibitors) and fenoxycarb (which is not a cholinesterase inhibitor). Those acting as cholinesterase inhibitors are neurotoxic agents that can have additive effects with organophosphates (OPs). They can be very acutely toxic, but do not bind as tightly to the sites of action as do the OPs.

A compound that causes excessive nerve transmission at (cholinergic) synapses by blocking ability of cholinesterase to break down acetylcholine into acetic acid and choline. Chemicals with this activity include poisons of the nerve gas type as well as pesticides of the organophosphate or carbamate class.

A compound that causes excessive nerve transmission at (cholinergic) synapses by blocking ability of cholinesterase to break down acetylcholine into acetic acid and choline. Chemicals with this activity include poisons of the nerve gas type as well as pesticides of the organophosphate or carbamate class.

(in dogs)- A syndrome which may be accompanied by signs of polydipsia [excessive, extended thirst], polyuria [passing a large volume of urine in a given period], abdominal distension, lethargy, muscular weakness, and testicular shrinkage.

Effect associated with certain organophosphates which starts several weeks following recovery from acute toxicity. Signs usually start at the extremities, arms and legs. Can be permanent or temporary and may be accompanied by nervous tissue degeneration.

Brings about a change in the ecosystem. Since we do not understand completely the function and structure of most ecosystems, we generally are not aware of all the ecological effects of our actions. Ecological effects which could result from use of chemical insecticide products outdoors include harm to birds and beneficial insects as well as poisoning of fish, and aquatic invertebrates.

An exogenous agent that interferes with the synthesis, secretion, transport, binding action or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis, reproduction, development, and behavior.

The physical form in which insecticide products are marketed, generally a combination of the active ingredients with inert substances, other carriers, solvents, etc. The inert ingredients are not intended to act on the pest for which the product is labeled, although they may prove toxic to other pests or to non-target plants or animals. The resulting insecticide products may have the form of sprays, dusts, granules, pour-ons, aerosols, collars or wipes.

GABA is the acronym for Gamma Amino Butyric Acid, a neurotransmitter. GABA acts to stop transmission of impulses in vertebrates and invertebrates. It operates at sites in the choloride channel of the nerves in the central nervous system of mammals and throughout the nervous system of insects. Fipronil, type II pyrethroids and some organophosphates can act on various aspects of the GABA receptor.

Genetic Engineering is based on the technology which makes possible the ability to move genetic material (DNA) from one organism (a virus, fungus or animal) to another organism (a plant, animal or bacteria). Totally new life forms can be created by this technology. Thus these novel life forms can be patented.

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) defines the standards by which insecticide products must be registered. FIFRA requires that the technical chemicals in a product only be tested on birds, fish, and small mammals, not on trees or other plant life. In addition, the USEPA may waive the requirement for proof of efficacy. Once the technical chemical has fulfilled all requirements, the formulated products which contain that chemical undergo limited acute toxicity testing on laboratory animals as a minimum requirement.

A lethal dose for 50% of the test organisms. The dose of toxicant producing 50% mortality in a population. A value used in presenting mammalian toxicity, usually oral toxicity, expressed as milligrams of toxicant per kilogram of body weight (mg/kg).

The mass of tissues and organs separating the two lungs, between the sternum in the front and the vertebral column behind, and from the thoracic inlet above to the diaphragm below. It contains the heart and its large vessels, the trachea, esophagus, thymus, lymph nodes, and other structures and tissues, and is divided into anterior, middle and posterior and superior regions.

Synthetic insecticides and nerve toxins belonging to the pyrethroid class must be distinguished from the naturally occurring pyrethrin/pyrethrums isolated from chrysanthemums. Pyrethroids are much more potent, toxic, and significantly more persistent in the environment than are the plant-derived compounds (see Section 2, Overview, Part I-1 Pyrethroids for details). Occasionally, chemical company representatives try to blur this distinction by stating that pyrethroids are derived from the natural pyrethrums, but this is misleading. Pyrethroids are synthesized products designed to be more powerful and longer lasting insecticides than are the pyrethrums, partly because the latter are too easily destroyed by ultraviolet light.

The pesticide chemical in pure form (95-100% concentration) as it is manufactured by a chemical company prior to being formulated into wettable powders, dusts, emulsifiable concentrates, granules, etc.

(USEPA)- Formed in 1970, responsible for enforcement of the Federal Insecticide, Fungicide and Rodenticide Act, (FIFRA). Registers pesticide products if it is determined that they do not pose an “unreasonable” risk to human health and the environment when used as directed by product labeling.

A vascular reaction of the skin marked by the transient appearance of smooth, slightly cleaved elevated patches (eruptions), which are redder or paler than the surrounding skin and often attended by severe itching. The eruption rarely lasts longer than two days, but may exist in a chronic form.

Formed in 1970, responsible for enforcement of the Federal Insecticide, Fungicide and Rodenticide Act, (FIFRA). Registers pesticide products if it is determined that they do not pose an “unreasonable” risk to human health and the environment when used as directed by product labeling.

A hallucination of movement; a sensation as if the external world were revolving around the patient or as if he himself were revolving in space. The term is sometimes erroneously used as a synonym for dizziness.